Popping and Puffing of Cereal Grains: A Review

Accepted: 25/10/2014 Abstract Popping is a simultaneous starch gelatinization and expansion process, during which grains are exposed to high temperatures for short time. During this process, super heated vapour produced inside the grains by instantaneous heating, cooks the grain and expands the endosperm suddenly, breaking out the outer skin. Puffing is a similar process; differ from popping as a process in which controlled expansion of kernel is carried out, while the vapour pressure escapes through the micropores of the grain structure due to high pressure or thermal gradient. Popping and puffing imparts acceptable taste and desirable aroma to the snacks. There are different methods of popping/puffing used viz., conventional method of dry heat, sand and salt treated, hot air popping, gun puffing, popping in hot oil and by microwave heating. Though a wide range of cereals and millets such as rice, wheat, corn, sorghum, ragi, foxtail millet are used for popping/puffing; only few of them pop well. The reason behind this may be the factors which influence popping qualities of cereals, such as season, varietal difference, grain characteristics such as moisture content, composition of grain, physical characteristics, types of endosperm, and also the method of popping. Therefore, this paper aimed at providing brief review of popping characteristics of different cereal grains and popping methods in response to high popping yield and greater volume expansion ratio.